//敌人类

function Enemy(cxt,img,type,x,y,width,height){

    this.cxt = cxt;
    this.img = img;
    this.x = x;
    this.y = y;
    this.width = width;
    this.height = height;
    //敌人类型
    this.type = type;

    this.sp = 2;
    //移动的方向
    this.dir = null;
    //下个移动位置
    this.nextPosition = null;

    //记录已经走过的位置
    this.hadWalk = {};
}

Enemy.prototype = {
    //敌人在图片中对应的位置
    enemyMap : [{x:0,y:0},{x:40,y:0},{x:80,y:0},{x:120,y:0},{x:160,y:0},{x:200,y:0},{x:240,y:0},{x:280,y:0},{x:320,y:0},{x:360,y:0},
        {x:400,y:0},{x:440,y:0},{x:480,y:0},{x:520,y:0},{x:560,y:0},{x:600,y:0},{x:640,y:0},{x:680,y:0},{x:720,y:0},{x:760,y:0}],
    //画出敌人
    draw : function(){
        //冰冻中,画出冰冻图
        if(this.frozenTime > 0){

            Canvas.drawImg(this.cxt,this.img,this.enemyMap[this.type].x,this.enemyMap[this.type].y+40,this.width,this.height,this.x,this.y,this.width,this.height);
        }
        //画出正常图
        else Canvas.drawImg(this.cxt,this.img,this.enemyMap[this.type].x,this.enemyMap[this.type].y,this.width,this.height,this.x,this.y,this.width,this.height);
        //计算血量百分比
        var persen = Math.floor(this.life / this.maxLife * 100) / 2;
        //画出血量
        Canvas.fillRect(this.cxt,this.x-5,this.y-5,persen,3,"rgba(38,223,116,0.8)");
    },

    //更新敌人信息
    update : function(){
        //超出坐标
        if(this.x >= 500){
            return false;
        }

        var xIndex = parseInt(this.x / 50,10),
            yIndex = parseInt(this.y / 50,10);
        //判断是否有下个移动位置信息,或者下哥移动位置信息是否已经走到了
        if(!this.nextPosition ||
            ((this.x >= this.nextPosition.x - 5 && this.x <= this.nextPosition.x) && (this.y >= this.nextPosition.y - 5 && this.y <= this.nextPosition.y))
        ){
            //走到最右侧
            if(xIndex + 1 >= 10){
                xIndex = -1;
            }
            else{
                //判断往下能否走
                if(MapData[xIndex][yIndex+1] && !this.hadWalk[xIndex+"_"+(yIndex+1)]){

                    this.dir = "down";
                    yIndex += 1;
                }
                //判断往右能否走
                else if(MapData[xIndex+1][yIndex]  && !this.hadWalk[(xIndex+1)+"_"+yIndex]){
                    this.dir = "right";
                    xIndex += 1;
                }
                else if(MapData[xIndex][yIndex-1] && !this.hadWalk[xIndex+"_"+(yIndex-1)]){
                    this.dir = "up";
                    yIndex -= 1;
                }
                else if(MapData[xIndex-1][yIndex] && !this.hadWalk[(xIndex-1)+"_"+yIndex]){
                    this.dir = "left";
                    xIndex -= 1;
                }
            }
            //是否走到最右侧
            if(xIndex == -1){
                this.nextPosition = {x:500,y:yIndex*50+5};
            }
            //设置下个移动位置
            else {
                this.nextPosition = {x:xIndex*50+5,y:yIndex*50+5};
                //记录已经走过的位置
                this.hadWalk[xIndex+"_"+yIndex] = true;
            }

        }


        //移动
        switch(this.dir){

            case "down":
                this.y += this.sp;
                break;
            case "up":
                this.y -= this.sp;
                break;
            case "left":
                this.x -= this.sp;
                break;
            case "right":
                this.x += this.sp;
                break;
            default:

                break;
        }

    }

}

//更新所有敌人信息
function updateEnemy(){

    var enemy;

    for(var i=0,l=Game.enemyList.length;i<l;i++){

        enemy = Game.enemyList[i];

        if(!enemy)continue;

        enemy.update();
    }

}

//画出所有敌人
function drawEnemy(){

    var enemy;

    for(var i=0,l=Game.enemyList.length;i<l;i++){

        enemy = Game.enemyList[i];

        if(!enemy)continue;

        enemy.draw();
    }

}